RU2420545C2 - Aqueous dispersion of copolymerisation products, use thereof, preparation method thereof (versions thereof), aqueous coating agent, coating made therefrom and coating method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: disclosed aqueous dispersion of copolymerisation products containing A) one or more hydroxy-functional copolymerisation products, obtained from the following (wt %): non-hydroxyl containing ester of (meth)acrylic acid and/or vinylaromatic compounds (53.5-87), hydroxy-functional ester of (meth)acrylic acid (2.5-45.9), ionic and/or potentially ionic monomers (0.6-19) capable of radical copolymerisation, as well as, if necessary, other monomers capable of radical copolymerisation which are different from compounds of components a)-c) (0-43.4) and B) at least one hydroxy-functional polycarbonate-polyol as a reactive diluent. Disclosed also is an aqueous coating agent which contains one or more of the disclosed aqueous dispersions of copolymerisation products and at least one cross-linking agent which interacts with hydroxyl groups.

EFFECT: disclosed aqueous dispersions have low solvent content and enable to obtain coatings with high level of resistance of lacquer films, with high scratch resistance and acid resistance.

5 cl, 1 tbl, 12 ex

Description

The invention relates to an aqueous dispersion of polymers with a low solvent content based on hydroxyfunctional copolymerizates, especially to an aqueous dispersion of copolymerizates, its use and its preparation method (its variants), to an aqueous coating agent, a coating obtained from it and a method for producing a coating.

The introduction of coating systems (for example, described in German patent application DE-A 3209421 and in European patent applications EP-A 95263, EP-A 105293, EP-A 133949, EP-A 288763) of a water-borne binder based on copolymer. However, as a rule, they contain emulsifiers for stabilization and / or an increased amount of organic cosolvent.

The use of an increased amount of organic solvent is undesirable from an environmental point of view. However, they cannot be avoided in order to guarantee, upon receipt of the polymerizate, sufficient mixing ability and heat removal from the reaction mixture, as well as a certain minimum degree of filling of the reactor. In addition, the organic solvent leads to beneficial effects in aqueous coating agents, such as improved storage stability, pigment wettability, optical properties of films and filling.

The subsequent decrease in the solvent content in the copolymerizates or dispersions of the copolymerizates due to the technology is associated with high hardware and energy costs and, therefore, also with a high cost. Therefore, there is a need for aqueous dispersions of polymerizates, upon receipt of which it is possible to largely abandon the use of an organic solvent without compromising the technological and consumer properties.

Dispersions of copolymerizates that must be cured by a chemical reaction, for example with amino plastics blocked with a polyisocyanate or with a polyisocyanate, must contain a certain amount of reactive groups, for example hydroxyl groups. These groups are typically introduced into the copolymer when the hydroxy-functional ester of (meth) acrylic acid is shared during copolymerization. However, these starting materials are very expensive compared to (meth) acrylic acid esters that do not contain functional groups or also to styrene. In addition, it is often also necessary to use an increased amount of these starting materials in comparison with copolymers that are soluble in organic solvents in order to compensate for the hydrophilicity of the varnish film by means of an increased crosslink density.

One of the methods for producing secondary dispersions of hydroxy-functional copolymerizates with hydroxyl functional groups, in which solvents are largely avoided during polymerization, is described in European patent application EP-A 0758007. In this method, the commonly used solvent is completely or partially replaced by a simple hydroxy-functional polyester (with hydroxyl functional groups). This simple hydroxy-functional polyester is introduced into the secondary dispersion as a reactive diluent and, upon subsequent crosslinking, reacts with isocyanates or blocked isocyanates to form urethane. Therefore, it does not contribute to the volatilization of organic substances. However, it is indicated that the content of the polyester in the varnish leads in some cases, when used, to low resistance, for example, low scratch resistance.

It has now been found that aqueous dispersions of copolymerizates with a low solvent content and a high level of durability of varnish films, especially those with very good scratch and acid resistance based on hydroxy-functional copolymers (with hydroxyl functional groups) can be obtained if hydro-functional polycarbonates are used as a reactive diluent ( with hydroxyl functional groups).

Therefore, an object of the invention are aqueous dispersions of copolymerizates containing:

A) one or more hydroxy-functional copolymerizates derived from

a) not containing hydroxyl groups of esters of (meth) acrylic acid and / or vinyl aromas,

b) hydroxy-functional esters of (meth) acrylic acid,

c) capable of radical copolymerization of ionic and / or potentially ionic monomers, and

d) if necessary, other monomers capable of radical copolymerization, different from the compounds of components a) to c) and

B) at least one hydroxy-functional polycarbonate polyol as a reaction diluent.

The object of the present invention is also a method for producing dispersions of copolymerizates according to the invention, characterized in that at least one hydroxy-functional polycarbonate polyol is used as reaction diluent B) and one or more monomer mixtures are subjected to radical polymerization containing

a) a hydroxyl group-free ester of (meth) acrylic acid and / or vinyl aromatic compounds,

b) a hydroxy-functional ester of (meth) acrylic acid,

c) ionic and / or potentially ionic monomers capable of radical copolymerization; and

d) if necessary, other monomers capable of radical copolymerization, different from the compounds of components a) to c),

and then the copolymerizate thus obtained is dispersed in water before or after the addition of the neutralizing agent.

In addition, another object of the invention is the use of aqueous dispersions of the copolymerizates according to the invention to obtain scratch-resistant varnishes and coatings.

As the monomers of component a), acrylates and methacrylates (hereinafter referred to as (meth) acrylates) with 1-18 carbon atoms in the alcohol part of the ester groups are used. This alcohol moiety may be straight chain, branched or cycloaliphatic.

Suitable monomers of component a) are, for example, methyl-, ethyl-, n-propyl-, n-butyl-, isopropyl-, isobutyl-, tert.butyl-, isomeric pentyl-, hexyl-, 2-ethylhexyl-, octyl-, dodecyl-, hexadecyl-, octadecyl- or cyclohexyl-, trimethylcyclohexyl- and isobornyl- (meth) acrylates or acetoacetoxyethylmethacrylate. Suitable vinyl aromatic compounds are, in particular, styrene, optionally substituted styrene and vinyl toluene.

As a component a) can also be used any mixture of the above compounds.

As component b), ethylenically unsaturated hydroxyl group-containing monomers can be used, such as, for example, hydroxyalkyl esters of unsaturated carboxylic acids, preferably hydroxyalkyl (meth) acrylates with 2-12 carbon atoms, preferably 2-6 carbon atoms in the hydroxyalkyl radical.

Examples of such compounds are 2-hydroxyethyl (meth) acrylate, isomeric hydroxypropyl (meth) acrylates, 2-, 3- and 4-hydroxybutyl- (meth) acrylates, as well as isomeric hydroxyhexyl (meth) acrylates.

By (meth) acrylates in the context of the present invention is always meant both the corresponding acrylates and methacrylates.

Olefinically unsaturated monomers with carboxy groups or anhydride groups of carboxylic acids, such as, for example, acrylic acid, methacrylic acid, β-carboxyethyl acrylate, crotonic acid, fumaric acid, can be used as radical polymerizations of ionic and / or potentially ionic monomers of component c). , maleic anhydride, itaconic acid or monoalkyl ester of dibasic acids or anhydrides, such as, for example, monoalkyl ester of maleic acid. Acrylic acid and / or methacrylic acid are preferred.

Also suitable as component c) are also unsaturated radical polymerizable compounds with phosphate or phosphonate or sulfonic acid or sulfonate groups, such as, for example, those described in WO-A 00/39181 (p. 8, line 13 - p. 9, line 19), preferably 2-acrylamido-2-methyl-propanesulfonic acid.

Other compounds capable of radical polymerization can also be used as compounds of component d). They can be, for example, derivatives of acrylic or methacrylic acid, such as acrylamide, methacrylamide, acrylonitrile and methacrylonitrile, hereinafter simple vinyl ether and vinyl acetate. Other used, if necessary, components d) can be considered di - and more multifunctional (meth) acrylate monomers and / or vinyl monomers, such as, for example, hexanediol (meth) acrylate or divinylbenzene. As component d), polymerizable hydroxy functional monomers modified by alkylene oxides or chain extended with a number average molecular weight of ≤3000 g / mol, preferably ≤500 g / mol can also be used. As alkylene oxides, for example, ethylene, propylene or butylene oxide can be used, individually or in a mixture.

Other suitable components of d) are vinyl esters, for example, versatic acids, known under the trade name VEOVA ^™ 9, 10 and 11 (Resolution Performance Products). This is a complex vinyl ester with a highly branched structure of the general formula (I)

wherein R ² and R ³ are branched alkyl groups containing together 6, 7 or 8 carbon atoms for VEOVA 9, 10 and 11, and R ⁴ is methyl.

The glass transition temperature (T _g ) for VEOVA series homopolymers is indicated as 70 ° C (VEOVA 9), (-3) ° C (VEOVA 10) and (-40) ° C (VEOVA 11).

Other monomers used as component d) are alkoxypolyethylene glycol or alkoxypolypropylene glycol ethers of (meth) acrylic acid, formally obtained by esterification of the starting hydroxyethylene or hydroxypropylene polyethers of monohydric alcohols, for example methanol, ethanol, isopropanol or one of the isomers of methanol or butanol.

As the hydroxy-functional polycarbonate polyols B), preferably, the products of transesterification of simple diols, such as, for example, 1,4-butanediol, 1,6-hexanediol, di-, tri- or tetraethylene glycol, di-, tri- or tetrapropylene glycol, 3-methyl- 1,5-pentanediol or 4,4′-dimethylolcyclohexane and / or mixtures thereof with diaryl carbonates, for example diphenyl carbonate or dialkyl carbonates, such as dimethyl carbonate, diethyl carbonate, alkylene carbonates, such as ethylene carbonate or propylene carbonate or phosgene. If necessary, smaller multifunctional simple polyols such as trimethylolpropane, glycerol or pentaerythritol can also be used together in smaller amounts. The hydroxy-functional polycarbonate polyols B) used according to the invention have an average hydroxyl functionality of 1.6 to 6, preferably 1.8 to 3 and particularly preferably 1.9 to 2.3 and a number average molecular weight of 240 to 5000, preferably 500 to 3000 , particularly preferably from 700 to 1500 Daltons. The preparation of polycarbonate polyols suitable as component B) is preferably carried out according to the methods described in European patents EP 1404740 B1 (p.6-8, examples 1-6) and European patent application EP 1477508 A1 (p.5, example 3).

Particularly preferred components B) are based on 1,4-butanediol, 1,6-hexanediol or 3-methyl-1,5-pentanediol or on mixtures of the two diols mentioned above and have an average hydroxyl functionality of from 1.9 to 2.05.

The amount of component B) based on the sum of components A) and B) is usually from 5 to 60 wt.%, Preferably from 10 to 40 wt.% And particularly preferably from 15 to 30 wt.%

The polymerization of unsaturated monomers is carried out in a manner known to the skilled person. Typically, for this purpose, reactive diluent B) is introduced into the reaction vessel and unsaturated monomers are polymerized using a radical polymerization initiator.

If necessary, an organic solvent can be additionally used in a smaller amount. Suitable dissolution aids are conventional solvents known in the art of varnishes, such as, for example, alcohols, ethers, ethers, ethers, esters, ketones or non-polar hydrocarbons, or mixtures of these solvents. The solvent is used in such an amount that its content in the finished dispersion is from 0 to 5 wt.%. If required, the used solvent can again be partially removed by distillation.

The copolymerization is usually carried out at a temperature of from 40 to 200 ° C, preferably from 60 to 180 ° C, particularly preferably from 80 to 160 ° C.

Suitable initiators of the polymerization reaction are, for example, organic peroxides, such as di (tert.butyl) peroxide or tert.butylperoxy-2-ethylhexanoate and azo compounds, such as nitrile of azodiisobutyric acid. The number of initiators used depends on the desired molecular weight. In order to increase process safety and facilitate manipulation, peroxide initiators can also be used as a solution in suitable organic solvents of the above kind.

In one of the preferred embodiments of the method, two-stage addition of unsaturated monomers of the above monomers is carried out and their polymerization is carried out in the presence of component B). In this case, in the first step (I), a hydroxy-functional copolymer is obtained with a hydroxyl number from 12 to 200, preferably from 15 to 190, particularly preferably from 100 to 165 mg of potassium hydroxide per gram of solid, and with an acid number from 0 to 50, preferably from 0 to 20, particularly preferably from 0 to 15 mg of potassium hydroxide per gram of solid, from 55 to 90 wt.% Of component a), from 2.5 to 50 wt.% Of component b), from 0 to 6.5 wt. % by weight of component c) and from 0 to 42.5% by weight of component d). In the next step (II), in the reaction mixture obtained in step (I), another polymerizate is obtained from components a) -d), the polymerizate having a hydroxyl number from 20 to 200, preferably from 20 to 190, particularly preferably from 50 to 165 mg potassium hydroxide per gram of solid and with an acid number of from 50 to 200, preferably from 75 to 185, particularly preferably from 77 to 150 mg of potassium hydroxide per gram of solid. In this case, the polymerizate from stage (II) is obtained from 45 to 80 wt.% Component a), from 5 to 50 wt.% Component b), from 6.5 to 25 wt.% Component c) and from 0 to 43, 5 wt.% Component d). The percentage of the composition of the polymerizate in accordance with the polymerizate in the amount of 100 wt.%. The amount of monomers in both stages of the preparation of the polymerizate is selected so that the mass ratio of the polymerizate from stage (I) to the polymerizate from stage (II) is from 10: 1 to 1: 2, preferably from 6: 1 to 2: 1.

The mass ratio of the components of the synthesis from a) to d) is usually chosen so that the copolymerizate has a hydroxyl number of from 12.5 to 200 mg of potassium hydroxide per gram of solid, preferably from 15 to 190 mg of potassium hydroxide per gram of solid, and particularly preferably 95 to 165 mg of potassium hydroxide per gram of solid and an acid value of 4.5 to 150 mg of potassium hydroxide per gram of solid, preferably 7 to 75 mg of potassium hydroxide per gram of solid, particularly preferably 10 to 60 m potassium hydroxide per gram of solid. The resulting polymerizate from stages (I) and (II) is obtained from 54 to 83 wt.%, Preferably from 53.5 to 87 wt.% Of component a), from 2.5 to 50 wt.%, Preferably from 3 to 50 wt.% component b), from 0.6 to 19 wt.%, preferably from 1 to 12.5 wt.% component c) and from 0 to 43.5 wt.%, preferably from 0 to 43 wt.% component but).

Instead of a multi-stage polymerization process, it is also possible to carry out the process continuously (gradient polymerization), when the monomer mixture is added according to the composition of the varying composition of the copolymerizate or copolymerizates A), and preferably the amount of hydrophilic monomers according to components c) and, possibly, a) to the end of the feed exceeds the feed at the beginning quantity.

The copolymers obtained by the method according to the invention have a number average molecular weight M _{n of} from 500 to 30,000 g / mol, preferably from 1000 to 15000 g / mol, particularly preferably from 1500 to 10000 g / mol.

Before, during or after the dispersion of the hydroxy-functional copolymerizates A) in water, the acid groups present in them are at least partially converted to the salt form by the addition of an appropriate neutralizing agent. Suitable neutralizing agents are organic amines or water-soluble inorganic bases, such as, for example, soluble metal hydroxides, metal carbonates or hydrogen carbonates.

Examples of suitable amines are N-methylmorpholine, triethylamine, ethyldiisopropylamine, N, N-dimethylethanolamine, N, N-dimethylisopropanolamine, N-methyldiethanolamine, diethylethanolamine, triethanolamine, butanolamine, morpholine, 2-aminomethanediolamine-2. Ammonia can also be partially used in mixtures. Particularly preferred are triethanolamine, N, N-dimethylethanolamine and ethyldiisopropylamine.

The neutralization agent is added in such an amount that the total theoretical degree of neutralization (acid groups) is from 40 to 150%, preferably from 60 to 120%. Moreover, by the degree of neutralization is meant the ratio of the introduced main groups of the neutralization component to the acid functional groups of the copolymerizate. The pH of the aqueous dispersion of the binder according to the invention is from 6 to 10, preferably from 6.5 to 9.

Aqueous dispersions of the copolymerizates according to the invention have a solids content of from 25 to 70 wt.%, Preferably from 35 to 60 wt.%, Particularly preferably from 40 to 55 wt.%, And also the content of organic solvents from 0 to 5 wt.%, Preferably from 0.5 to 3.5 wt.%.

The dispersions of the copolymerizates of the invention can be processed into aqueous coating agents. Moreover, by combining with cross-linking agents, depending on the reactivity or, if necessary, by blocking the cross-linking agent, both one-component and also two-component varnishes can be obtained. Moreover, in the sense of the present invention, under one-component varnishes is meant a coating agent in which the binder component and the crosslinking component can be stored together, and there is no noticeable crosslinking reaction or harmful effects when applied. The crosslinking reaction occurs only when applied after activation of the crosslinking agent. This activation may be caused, for example, by an increase in temperature. By bicomponent varnishes in the sense of the present invention is meant a coating agent in which the binder component and the crosslinking component, in view of their high reactivity, must be in separate containers. Both components are mixed only shortly before coating, and then they usually react without additional activation. But catalysts or an elevated temperature may also be used to accelerate the crosslinking reaction.

Therefore, an object of the present invention is also an aqueous coating agent, comprising:

i) one or more aqueous dispersions of the copolymerizates of the invention, as well as

ii) at least one crosslinking agent capable of interacting with hydroxyl groups.

Suitable crosslinking agents that are reactive with hydroxyl groups are, for example, a polyisocyanate crosslinking agent, amide and aminoformaldehyde resins, phenolic resins, aldehyde and ketone resins, such as, for example, phenol formaldehyde resins, resoles, furan resins, urea resins urea esters, triazine resins, melamine resins, benzoguanamine resins, cyanamide resins, aniline resins, such as those described by H. Wagner, HFSarx, Artificial Resin Varnish, Carl Hanser Verlag München, 1971.

Polyisocyanates are preferably used as the crosslinking agent. Such polyisocyanates usually contain two or more isocyanate groups in the molecule and are based, for example, on isophorondiisocyanate, hexamethylene diisocyanate, 1,4-diisocyanatocyclohexane, bis (4-isocyanatocyclohexane) methane, 1,3-diisocyanatobenzene, triisocyanato-ononane or , 6-toluene diisocyanates (TDI) and may also contain urethane, isocyanurate and / or biuret groups. If necessary, the polyisocyanates can also be blocked.

Especially preferred is the use of low viscosity polyisocyanates of the above type based on aliphatic or cycloaliphatic isocyanates. If necessary, they can also be hydrophilized.

The polyisocyanates used as the crosslinking agent typically have a viscosity of from 10 to 5,000 mPa · s at 23 ° C., and if viscosity control is desired, this can be achieved by using a small amount of inert solvents in the mixture.

The copolymerizates of the invention are usually quite hydrophilic, so that even hydrophobic crosslinking resins can be dispersed without additional emulsifiers. However, this does not exclude the possibility of using emulsifiers from the outside.

Water-soluble or dispersible polyisocyanates are prepared, for example, by modification with carboxylate, sulfonate, and / or polyethylene oxide and / or polypropylene oxide groups. Hydrophylation of polyisocyanates is possible, for example, by reaction with monatomic hydrophilic polyester alcohols in an amount less than theoretical. The preparation of such hydrophilic polyisocyanates is described, for example, in European patent application EP-A 0540985 (from p. 3, line 55 to p. 4, line 5).

Also well described are those described in European patent application EP-A 959087 (p. 3, lines 39-51) containing allophanate groups of polyisocyanates obtained by reacting depleted monomers of polyisocyanates with polyethylene oxide polyether alcohols under conditions of allofanatization. Water-dispersible mixtures of polyisocyanates based on triisocyanatononan, as well as polyisocyanates hydrophilized by ionic groups (sulfonate, phosphonate groups), such as those described in German patent application DE-A 10007821 (from p. 2, line 66 to p. 3, line 5) are also suitable. , for example, as described in German patent application DE-A 10024624 (p. 3, lines 13-33).

In principle, it is of course possible, of course, to use mixtures of various crosslinking resins.

Before, during, or after the preparation of the aqueous dispersion of the copolymerizates of the invention, auxiliary agents and additives conventional in varnish technology can be added, such as, for example, antifoam agents, thickeners, pigments, dispersants, catalysts, anti-film agents, anti-precipitants or emulsifiers.

These auxiliary agents and additives can also be added to coating agents containing aqueous dispersions of the copolymerizates of the invention.

Aqueous coating agents containing the aqueous dispersions of the copolymerizates of the invention are suitable for use in all fields that employ aqueous paint systems and coating systems with high demands on film stability. For example, for coating on the surface of mineral building materials, for varnishing and sealing (sealing) of wood and wood materials, coating on metal surfaces (coatings for metals), coating and varnishing of layers containing asphalt or bitumen, varnishing and sealing (sealing) ) various plastic surfaces (plastic coatings), as well as for varnishes with a mirror finish.

Aqueous coating agents containing the aqueous dispersions of the copolymerizates of the invention are suitable for the preparation of solvent-poor primers, fillings of pigmented or transparent coating varnishes, transparent varnishes and gloss-lacquers, and single-layer varnishes, for example, in the field of industrial varnishing, initial or repair varnishing cars. Particularly suitable are aqueous dispersions of the copolymerizates according to the invention for the preparation of transparent aqueous varnishes for the initial lacquering of automobiles, which require particularly high scratch resistance and chemoresistance.

The invention also relates to a method for producing coatings, characterized in that a coating agent containing a dispersion of the copolymers of the invention is applied to the substrate and then cured. Thus obtained coatings, as a rule, have a residual gloss after low tide of more than 90%.

In this case, the curing of the coating agent is usually carried out at a temperature of from 0 to 180 ° C, preferably from 18 to 160 ° C, particularly preferably from 40 to 140 ° C.

The coating can be obtained by various spraying methods, such as, for example, pneumatic spraying, vacuum or electrostatic spraying using a single-component or, possibly, two-component spraying system. However, varnishes and a coating agent containing aqueous dispersions of the hydroxy-functional copolymerizates of the invention can also be applied by other methods, for example with a brush, rollers or doctor blades.

Examples

Unless otherwise indicated, all percentages are mass percent.

The viscosity was measured on a Physica Viscolab® LC3 ISO conical plate viscometer, Physica, Stuttgart, Germany, according to DIN 53019 at a shear gradient of 40 s ^-1 .

The average particle size was determined by laser correlation spectroscopy (Zetasizer® 1000, Malvern Instruments, Hervenberg, Germany).

The indicated hydroxyl numbers are calculated based on the monomers used.

Acid numbers: determination methods = DIN ISO 3682.

Example 1

469 g of 1,6-hexanediol and 454 g of ε-caprolactone, as well as 0.2 g of titanium tetraisopropylate, were placed in a 4-liter multi-necked flask with a stirrer and heated under an inert gas (nitrogen) stream to an oil bath of 110 ° C. Then, 401 g of dimethyl carbonate was added to the reaction mixture over the course of 15 minutes, after which it was kept under a reverse flow for another 24 hours. Then, the mixture of dimethyl carbonate and methanol was removed from the reaction mixture by means of a distillation column at normal pressure, the temperature of the oil bath being continuously increased from 110 ° C to 150 ° C for 7 hours. Then, the temperature of the oil bath was reduced to 100 ° C, as well as the pressure was reduced to 20 mbar (absolute) with the simultaneous removal of methanol and residual dimethyl carbonate. After that, the temperature of the oil bath was increased over 5 hours to 180 ° C and kept at this temperature for 2 hours. Then the reaction mixture was cooled to room temperature and mixed with 0.2 g of dibutyl phosphate. A polycarbonate ether diol with a hydroxyl number of 113 mg potassium hydroxide / g was obtained.

Example 2

They acted as in Example 1, with the difference that 861 g of 1,6-hexanediol and 0.2 g of ytterbium (III) acetylacetonate were placed in the flask and 826 g of dimethyl carbonate were pumped. The addition of 0.2 g of dibutyl phosphate in Example 1 was not carried out.

A polycarbonate diol with a hydroxyl number of 109 mg potassium hydroxide / g was obtained.

Example 3

The procedure was carried out as in Example 1, with the difference that 616 g of 1,6-hexanediol, 1408 g of 1,4-butanediol and 0.2 g of ytterbium (III) acetylacetonate were placed in the flask and 2477 g of dimethyl carbonate were pumped. The addition of 0.2 g of dibutyl phosphate in Example 1 was not carried out.

A polycarbonate diol with a hydroxyl number of 113 mg potassium hydroxide / g was obtained.

Example 4

A total of 34092 g of 3-methyl-1,5-pentanediol with 8.0 g of ytterbium (III) acetylacetonate, as well as 10223 g of dimethyl carbonate at 80 ° С were placed in a 60-liter pressurized reactor with a distillation section, a stirrer and a collector (receiver). . Then the reaction mixture was heated under nitrogen for 2 hours to 150 ° C and kept for 2 hours with stirring and with a reverse flow (reflux), and the pressure was increased to 3.9 bar (absolute). After that, the cleavage product, methanol in a mixture with dimethyl carbonate, was removed by distillation, the pressure being continuously reduced over a total of 2.2 bar over 4 hours. Then the distillation process was stopped and another 10223 g of dimethyl carbonate was pumped into the reaction mass at 150 ° С and kept for 2 h with stirring and with a reverse flow, the pressure being increased to 3.9 bar (absolute). After this, the cleavage product, methanol mixed with dimethyl carbonate, was removed again by distillation, the pressure being continuously reduced over a total of 2.2 bar over 4 hours. Then the distillation process was stopped and another 7147 g of dimethyl carbonate was pumped into the reaction mixture at 150 ° С and kept for 2 hours with stirring and with a reverse flow, the pressure being reduced to normal for 4 hours. Then the reaction mixture was heated for 2 hours to 180 ° C and kept at this temperature and with stirring for 2 hours. Immediately after this, the temperature was reduced to 130 ° C and a nitrogen stream (5 l / h) was passed through the reaction mixture, while the pressure was reduced to 20 mbar. After that, the temperature was raised over 4 hours to 180 ° C and held for 6 hours. In this case, additional removal of methanol from the reaction mixture in a mixture with dimethyl carbonate was carried out.

After blowing and cooling the reaction mixture to room temperature, a liquid colorless oligocarbonate diol was obtained with the following characteristics:

M _n = 675 g / mol; hydroxyl number = 166.0 mg potassium hydroxide / g;

viscosity: 6940 MPa · s at 23 ° C and D: 16.

Example 5

In a 10-liter reaction vessel equipped with a device for stirring, cooling, and heating, 600 g of polycarbonate diol according to Example 1 were placed and heated to 143 ° C. At this temperature, a solution of 7.75 g of tert-butyl peroxide in 7.75 g of Dowanol® PnB was added dropwise over 20 minutes. Then a monomer mixture of 81.5 g of 2-ethylhexyl acrylate, 566.5 g of hydroxyethyl methacrylate, 435 g of butyl methacrylate, 567.5 g of isobornyl methacrylate and 135 g of styrene were dosed, and a solution of 27.75 was simultaneously dosed for 4.5 hours. g of di-tert-butyl peroxide in 34.25 g of Dowanol® PnB. At this temperature, the reaction mixture was kept for about 20 minutes. After this, a monomer mixture of 122.5 g of methyl methacrylate, 172.75 g of hydroxyethyl methacrylate, 96 g of butyl acrylate and 46.25 g of acrylic acid was dosed, and at the same time, a solution of 7.75 g of tertoxide was dosed for 1.5 hours. butyl in 25 g of Dowanol® PnB. Then it was stirred for 1 hour at a temperature of 143 ° C, after which it was cooled to 100 ° C and 29.25 g of N, N-dimethylethanolamine was added. After homogenization for 30 minutes, it was dispersed with 3400 g of water at 80 ° C. for 2 hours. Received a dispersion of copolymerizates with the following characteristics:

The content of hydroxyl groups (solid, calculated theoretically) 4.3% Acid number (solid) 14 mg KOH / g Solids content 45.0% Viscosity 850 mPa s / 23 ° C PH value (10% in water) 8.5 Degree of neutralization 105% Average particle size 105 nm Co-solvent 1.1 wt.%

Example 6

600 g of polycarbonate diol according to Example 2 were placed in a 10 L reaction vessel equipped with a device for stirring, cooling, and heating and heated to 143 ° C. At this temperature, a solution of 7.75 g of tert-butyl peroxide in 7.75 g of Dowanol® PnB was added dropwise over 20 minutes. Then, a monomer mixture of 81.5 g of 2-ethylhexyl acrylate, 566.5 g of hydroxyethyl methacrylate, 435 g of butyl methacrylate, 567.5 g of isobornyl methacrylate and 135 g of styrene were dosed, and a solution of 27.75 was simultaneously dosed for 4.5 hours. g of di-tert-butyl peroxide in 34.25 g of Dowanol® PnB. At this temperature, the reaction mixture was kept for about 20 minutes. After that, a monomer mixture of 122.5 g of methyl methacrylate, 172.75 g of hydroxyethyl methacrylate, 96 g of butyl acrylate and 46.25 g of acrylic acid was dosed, and at the same time, a solution of 7.75 g of tertoxide was dosed for 1.5 hours. butyl in 25 g of Dowanol® PnB. Then it was stirred for 1 hour at a temperature of 143 ° C, after which it was cooled to 100 ° C and 29.25 g of N, N-dimethylethanolamine was added. After homogenization for 30 minutes, it was dispersed with 3625 g of water at 80 ° C for 2 hours. Received a dispersion of copolymerizates with the following characteristics:

The content of hydroxyl groups (solid, calculated theoretically) 4.3 Acid number (solid) 15 mg KOH / g Solids content 43.5% Viscosity 400 MPa · s / 23 ° С PH value (10% in water) 8.5 Degree of neutralization 105% Average particle size 110 nm Co-solvent 1.0 wt.%

Example 7

In a 6-liter reaction vessel equipped with a device for stirring, cooling and heating, 600 g of polycarbonate diol according to Example 3 were placed and heated to 143 ° C. At this temperature, a solution of 7.75 g of di-tert-butyl peroxide in 7.75 g of Dowanol® PnB was added dropwise over 20 minutes. Then, a monomer mixture of 81.5 g of 2-ethylhexyl acrylate, 566.5 g of hydroxyethyl methacrylate, 435 g of butyl methacrylate, 567.5 g of isobornyl methacrylate and 135 g of styrene were dosed, and a solution of 27.75 was simultaneously dosed for 4.5 hours. g of di-tert-butyl peroxide in 34.25 g of Dowanol® PnB. At this temperature, the reaction mixture was kept for about 20 minutes. After that, a monomer mixture of 122.5 g of methyl methacrylate, 172.75 g of hydroxyethyl methacrylate, 96 g of butyl acrylate and 46.25 g of acrylic acid was dosed, and at the same time, a solution of 7.75 g of tertoxide was dosed for 1.5 hours. butyl in 25 g of Dowanol® PnB. Then it was stirred for 1 hour at a temperature of 143 ° C, after which it was cooled to 100 ° C and 29.25 g of N, N-dimethylethanolamine was added. After homogenization for 30 minutes, it was dispersed with 3625 g of water at 80 ° C for 2 hours. Received a dispersion of copolymerizates with the following characteristics:

The content of hydroxyl groups (solid, calculated theoretically) 4.3% Acid number (solid) 14 mg KOH / g Solids content 43.5% Viscosity 2360 MPa · s / 23 ° С PH value (10% in water) 8.5 Degree of neutralization 105% Average particle size 130 nm Co-solvent 1.1 wt.%

Example 8

In a 6-liter reaction vessel equipped with a device for stirring, cooling and heating, 600 g of polycarbonate diol according to Example 4 were placed and heated to 143 ° C. At this temperature, a solution of 7.75 g of di-tert-butyl peroxide in 7.75 g of Dowanol® PnB was added dropwise over 20 minutes. Then a monomer mixture of 595.25 g of hydroxyethyl methacrylate, 487.75 g of butyl methacrylate, 692.5 g of isobornyl methacrylate and 135 g of styrene was dosed, and at the same time a solution of 27.75 g of di-tert-butyl peroxide in 34 was simultaneously dosed 25 g of Dowanol® PnB. At this temperature, the reaction mixture was kept for about 20 minutes. After that, a monomer mixture of 102.5 g of methyl methacrylate, 173 g of hydroxyethyl methacrylate, 96 g of butyl acrylate and 75 g of acrylic acid was dosed, and at the same time, a solution of 7.75 g of di-tert-butyl peroxide in 25 g of Dowanol was simultaneously dosed ® PnB. Then it was stirred for 1 hour at a temperature of 143 ° C, after which it was cooled to 100 ° C and 97 g of N, N-dimethylethanolamine was added. After homogenization for 30 minutes, dispersed with 3500 g of water at 80 ° C for 2 hours. Received a dispersion of copolymerizates with the following characteristics:

The content of hydroxyl groups (solid, calculated theoretically) 4.4% Acid number (solid) 21 mg KOH / g Solids content 44.5% Viscosity 1060 MPa · s / 23 ° С PH value (10% in water) 8.5 Degree of neutralization 105% Average particle size 94 nm Co-solvent 1.0 wt.%

Example 9 Comparative (European patent application EP-A 0758007, Example 1)

116 g of butyl glycol and 150 g of Desmophen® V218 (propylene oxide and glycerol polyester, hydroxyl number 245 mg potassium hydroxide / g, Bayer AG, Leverkusen, were placed in a 6 L reaction vessel equipped with a stirrer, cooling and heating device, Germany) and heated to 155 ° C. At this temperature, 321 g of butyl acrylate, 366 g of styrene and 198 g of hydroxyethyl methacrylate were dosed for 2 hours, and a solution of 17.1 g of di-tert-butyl peroxide in 28.6 g of butyl glycol was dosed. Then, a monomer mixture of 83 g of hydroxyethyl methacrylate, 180 g of butyl acrylate, 139 g of styrene and 34 g of acrylic acid was dosed for 1 hour, and a solution of 12.9 g of di-tert-butyl peroxide in 21.4 g of butyl glycol was also dosed. After this was stirred for 2 hours at a temperature of from 150 to 155 ° C, and then cooled to 100 ° C and 50 g of dimethylethanolamine was added. After 30 minutes of homogenization, they were dispersed for 2 hours at 80 ° C from 1980 g of water. Received a dispersion of copolymerizate with the following characteristics:

The content of hydroxyl groups (solid, calculated theoretically) 3.2% Acid number (solid) 18 mg KOH / g Solids content 40% Viscosity 830 MPa · s / 23 ° С PH value (10% in water) 9,4 Degree of neutralization one hundred% Average particle size 51 nm Co-solvent 4.0 wt.%

Example 10 Comparative (European patent EP 947557, Example 3)

186 g of butyl glycol and 186 g of solvent-naphtha solvent (naphtha) were placed in a 6-liter reaction vessel equipped with a device for stirring, cooling, and heating and heated to 145 ° C. At this temperature, a mixture of 1) was dosed for 3 hours from 750 g of methyl methacrylate, 125 g of styrene, 445 g of hydroxyethyl methacrylate, 538 g of butyl acrylate and 87 g of butyl methacrylate, and immediately after that, a mixture was dosed for 1.5 hours 2) of 128 g of methyl methacrylate, 180 g of hydroxyethyl methacrylate, 100 g of butyl acrylate and 60 g of acrylic acid. In parallel with this, a solution of 88 g of di-tert-butyl peroxide in 70 g of a 1: 1 mixture of butyl glycol and solvent-solvent naphtha was dosed for 5 hours. Then it was stirred for 2 hours at a temperature of 145 ° C, after which it was cooled to 100 ° C and 76 g of N, N-dimethylethanolamine was added. After 30 minutes of homogenization, dispersed for 2 hours at 80 ° C with 2700 g of water. Received a dispersion of a copolymerizate with the following characteristics:

The content of hydroxyl groups (solid, calculated theoretically) 3.3% Acid number (solid) 18 mg KOH / g Solids content 43.8% Viscosity 1400 MPa · s / 23 ° С PH value (10% in water) 8.1 Degree of neutralization 105% Average particle size 110 nm Co-solvent 7.7 wt.%

Example 11 Polyisocyanate Crosslinking Agent

3500 g of Bayhudur® XP 2570 (Bayer AG, Leverkusen) and 1500 g of Desmodur® XP 2410 (Bayer AG, Leverkusen) were dosed sequentially in a 6 L reaction vessel equipped with a stirrer, cooling and heating device and homogenized at 30 ° C. for 60 minutes. Then added 37 g of Tinuvin® 384-2 (Ciba, Basel) and 24 g of Tinuvin® 292 (Ciba, Basel) and homogenized for another 30 minutes. A hydrophilic mixture of polyisocyanates with an isocyanate content of 20.1% was obtained.

Application Example 12

Component A is mixed in a predetermined amount with Byk® 347 and diluted with water.

Before applying component A, component B is dispersed by means of a nozzle jet dispersant according to European patent EP-A 0685544 with a nozzle opening of 0.4 mm at a pressure of 50 bar. A mixed 2K-water transparent varnish was applied by means of a hand-held spray gun on aluminum sheet (scratch-resistant) or sheet steel (chemically resistant), on which an aqueous filler layer and a water-black basic varnish layer usual for initial auto-lacquering were applied. After application, the sheets are blown with air at room temperature for 5 minutes and then at 80 ° C for 10 minutes, and then dried at 130 ° C for 30 minutes. The dry layer thickness of the clear varnish was about 40 microns.

Table 1 Example 12 but b c d e Component A wt. parts wt. parts wt. parts wt. parts wt. parts Example 10 (comparative) 411.9 Example 9 (comparative) 339.9 Example 5 356.4 Example 6 372.1 Example 7 370.4 Byk® 347 2,3 2.2 2.2 2.2 2,3 Water 64,4 114.0 98.3 100.0 114.9 Component B Example 11 119.5 125.6 125.6 125.6 141.1 Scratch resistant after 17 hours % % % % % Residual gloss 45 84 83 82 58 Residual gloss after low tide 62 93 93 92 72 Chemical resistance ° C ° C ° C ° C ° C Dist water 36 46 > 68 > 68 36 1% NaOH 40 41 44 41 37 1% H ₂ SO ₄ 38 37 38 39 36

Scratch resistance

The scratch resistance test of the obtained transparent varnish was carried out according to DIN 55668.

The relative residual gloss in% was re-determined as the highest degree of gloss [20 °] after scratching according to DIN 5668 in comparison with the degree of gloss before scratching. The higher this value, the better the scratch resistance.

Chemoresistance

Chemostability is expressed in ° C. To do this, drip distilled water or 1% sodium hydroxide or 1% sulfuric acid onto a transparent lacquer coating and heat treat in a gradient oven. Determine the temperature at which the first visible damage to the transparent lacquer occurs. The higher this temperature, the more resistant is the coating of transparent varnish.

The example clearly shows that the varnishes of the dispersions of the copolymerizates of the invention have significantly better scratch resistance (residual gloss after low tide> 90%) with very good chemoresistance in comparison with the products of the prior art.

Claims (5)

1. An aqueous dispersion of copolymerizates to obtain a coating containing
A) one or more hydroxy-functional copolymerizates derived from
a) 53.5-87 wt.% not containing hydroxyl groups of the ester of (meth) acrylic acid and / or vinyl aromatic compounds,
b) 2.5-45.9 wt.% hydroxy-functional ester of (meth) acrylic acid,
c) 0.6-19 wt.% capable of radical copolymerization of ionic and / or potentially ionic monomers, as well as
d) 0-43.4 wt.%, if necessary, other capable of radical copolymerization of monomers, different from the compounds of components a) -c),
moreover, the sum of all components should be 100%,
and
B) at least one hydroxy-functional polycarbonate polyol as a reactive diluent. 2. An aqueous dispersion of copolymerizates according to claim 1, characterized in that the hydroxy-functional polycarbonate polyols B) have an average hydroxyl functionality of 1.6 to 6 and a number average molecular weight of 240 to 5000 Da. 3. The aqueous dispersion of copolymers according to claim 1, characterized in that the hydroxy-functional polycarbonate polyols B) are based on 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol or mixtures thereof. 4. The aqueous dispersion of copolymerizates according to claim 1, characterized in that the hydroxy-functional polycarbonate polyols B) have an average hydroxyl functionality of from 1.9 to 2.05. 5. Aqueous coating agent containing:
i) one or more aqueous dispersions of copolymerizates according to claim 1, and
ii) at least one crosslinking agent capable of reacting with hydroxyl groups.